Enantioselective Synthesis of 2-Arylbicyclo[1.1.0]butane Carboxylates
作者:Changming Qin、Huw M. L. Davies
DOI:10.1021/ol303217s
日期:2013.1.18
catalyst and catalyst loading to form either 2-arylbicyclo[1.1.0]butane carboxylates or cyclohexene derivatives. Both products are produced in a highly diastereoselective manner, with 2-arylbicyclo[1.1.0]butane carboxylates preferentially formed under low catalyst loadings. When the reaction is catalyzed by Rh2(R-BTPCP)4, the 2-arylbicyclo[1.1.0]butane carboxylates are generated with high levels of asymmetric
Enantioselective Synthesis of Cyclobutanes via Sequential Rh-catalyzed Bicyclobutanation/Cu-catalyzed Homoconjugate Addition
作者:Robert Panish、Srinivasa R. Chintala、David T. Boruta、Yinzhi Fang、Michael T. Taylor、Joseph M. Fox
DOI:10.1021/ja403811t
日期:2013.6.26
Enantiomerically enriched cyclobutanes are constructed by a three-component process in which t-butyl (E)-2-diazo-5-arylpent-4-enoates are treated with Rh2(S-NTTL)(4) to provide enantiomerically enriched bicyclobutanes, which can subsequently engage in homoconjugate addition/enolate trapping sequence to give densely functionalized cyclobutanes with high diastereoselectivity. This three-component, two-catalyst procedure can be carried out in a single flask. Rh-2(S-NTTL)(4)-catalyzed reaction of t-butyl (Z)-2-diazo-5-phenylpent-4-enoate gives the Buchner cyclization product in excellent enantioselectivity.
Hashimoto, Takuya; Naganawa, Yuki; Maruoka, Keiji, Journal of the American Chemical Society, 2009, vol. 131, p. 6614 - 6617